Mild steel carbon dioxide corrosion modelling in aqueous solutions

摘要

A model for prediction of corrosion of mild steel in aqueous solutions containing carbon dioxide is proposed. In this model, formation of protective corrosion product is not yet considered, species concentration at the surface was calculated by using molecular diffusion phenomena and the diffusion equations were solved using the finite difference method. Calculated electrochemical currents at the steel surface may be used to determine the corrosion rate. The model was verified experimentally under atmospheric pressure and the effect of parameters, such as liquid velocity and pH, was investigated. The model can predict the electrochemical reaction rates when they were controlled by diffusion or charge transfer. The model can also predict the concentration profiles of species in mass transfer layer and it appears that it comprises a solid approach for corrosion rate prediction in such environments.